Motor controller



A. J. CLINE.

MOTOR CONTROLLER. AP-PLICATION FILED DEC.30, 191's.

Patented Feb. 7, 1922.

javezaZE'r 4404 few UNITED STATES PATENT OFFICE.

ALLAN J. CLINE, OF CHICAGO, ILLINOIS.

MOTOR ooN'rRoLLER.

by which the operator can stop and start the motor as desired andcontrol the different motor speeds, together with devlces automaticallyoperating in accordance with conditions established in the motor circuitfor protecting the motor and controlling its rate of acceleration. Afurther object of the invention is to provide an arrangement in whichthe switch contacts and parts that directly control the armature circuitcan be located at a main controller station and the speed A regulatingand auxiliary control switches at a distant sta-.

' tion or stations, and in which arrangement it is only necessary toconnect small, light -wires to the control station or stations so thatthe latter can be light in construction andconveniently mounted on themachine within easy reach of the operator.

The conductors 10 and 11 of the supply circuit for the motor are-connected to the mains 12 by a line switch 13. The switches and otherparts which carry the armature current are located at the main station Aand the manually operable control switches are located at anotherstation or stations B and B.

The main controller station comprises a resistance 14 for the circuit ofthe armature Specification of Letters Patent.

Application filed December 30, 1918. I Serial No.

Patented Feb. '7, 1922.

A, separate electro-magnetic starting and reversing switches 15 and 16,which are provided with normally engaged and disengaged contacts andwhich operate to start and reverse the motor and a series of electromagnetic resistance switches 17, 18 and 19 which are arranged to cut outsuccessive portions of the armature resistance 14. The main station isalso provided with a relay 20 the coil of which is interposed in thearmature circuit and which if excessive current flows through thearmature circuit, is arranged to short circuit the field resistance.

The positive supply conductor 10 in the arrangement shown is connectedin parallel to the normally engaged or down contacts 21 ancl 22 of the,starting and reversing switches 15 and 16. The negative supply conductor11 is connected to one terminal of the armature resistance 14, the otherterminal of which is connected in parallel, by conductors 23 and 24, tothe normally disengaged or up contacts 25 and 26 of the starting andreversing switches. If desired, the normally disengaged contact 26 ofthe reversing switch may be connected by conductor 24 to some otherpoint of the main resistance 14. The armature terminals are connectedrespectively to the movable contacts of the starting and reversingswitches by the conductors 27 and 28, the coil of the relay 20 beinginterposed in the conductor 27. Preferably, as shown, a brake resistance29 is interposed between the normally engaged or down contacts of thestarting and reversing switches. a

When the starting switch 15 is energized, the motor circuit can betraced from the conductor 10, contact 22 of the reversing switch, byconductor 28 through the armature A, thence by conductor .27 through thecoil of the relay 20 and the up contact 25 of the starting switch,thence by conductor 23 through the armature resistance 14 to thenegative supply conductor 11. When the reversing switch is operated, themotor circuit is traced from positive conductor 10 through the brakeresistance 29 to the down contact 21 of the starting switch andconductor 27' through the armature A, thence by conductor 28 to thenormally disengaged or up contact 26 of the reversing switch and byconductors 24 and 23 through the armature resistance to the negativeconductor 11. When the operation of the motor is stopped, a circuit isformed from its positive terminal through conductor 28, down contact 22of the reversing switch 16,

' through the brake resistance 29 and down the usual manner to cut outdifferent sections of the armature resistance but, in the arrangementshown, these switches are only brought into operation when the motor isrunning in a normal direction.

The main controller station is also provided with a relay havingnormally open contacts 31 and 32 which are interposed re- "spectively inthe energizing circuits for the starting switch 15 and for theresistance switches 17, 18 and 19.

The controlling station B comprises a master control or speed regulatingswitch arm 33 of conducting material pivoted between its ends andarranged to engage and supply current to a number of contact buttons andsegments. The movement of the switch arm in opposite directions islimited by a fixed stop 34 and in one direction b a pivoted or movablestop 35. Current is supplied for the control circuit from the positiveconductor 10 of the main circuit by a conductor 36 which is always inelectrical connection with the master control or speed regulating switcharm 33 through the medium of a contact se ment 37. In the normal or idleposition of e master control switch, it engages the movable stop anddead contacts 38 and 39. As the switch is shifted in right handdirection, it successively engages two contact buttons 40 and 41 whichsupply current to the relay 30. As the switch is further shifted inright hand direction, it is disengaged from the contact button.41 andengages a segment 42 which supplies current to a holding circuit forrelay 30 and to'the starting switch 15 during further forward movementof the arm. After energizing the starting switch 15, the switch arm isarranged to successively engage two contact buttons 43' and 44 and acontact segment-45 which are respectively connected to the coils of theresistance switches 17, 18 and 19 which control the acceleration of themotor to what may be termed normal running speed. During the movement ofthe main controlling switch thus far described, it is in engagement witha contact segment 46 which supplies current to the shunt field F of themotor. After engaging the contact segment 45, the switch arm can bedisengaged from the segment 46 and arranged to cooperate with thecontacts of a field resistance 47 to further accelerate the motor speed.By shifting the movable stop 35, the master control switch can be movedfrom normal or idle position in left hand direction into engagement witha contact button 48 which supplies current to the reversing switch 16.

Auxiliary control or push button switches are also provided, either atthe control station B or at another control station or stations B.Preferably, as shown, the auxiliary control station comprises a springheld push button switch 49 having normally en aged contacts interposedin the circuit for ho ding the relay 30 in operated condition and forenergizing the starting switch 15 and two spring held push buttonswitches 50 and 51 having normally open contacts which are arranged tosupply current respectively to the relay 30 for running, and to thestarting switch 15 independently of the relay, for inching. lreferably,the push button switch 50 is provided with a pair of normally closedcontacts which are interposed in the energizin circuit of the auxiliaryor resistance switches 17, 18 and 19, and the switch button is providedwith a projecting lug 52 which may be moved through a notch in astationary holding glate 53 and then, by partially rotating the utton,the latter may be held out of engagement with its normally engagedcontacts.

The push button station is also preferably provided with a switchcomprising two sets of normally closed contacts 54 and 55 which circuit0 the starting relay and the feed conductor to the push button switches50 and 51. v

The movable members of the sets of contacts 54 and 55 are preferablyeach provided with a push button and are connected by an oscillatingmember 56 which is plvoted between its ends so that when one button isdepressed the other is raised. A spring 57 cooperates with the member 56to hold the cont-acts either open or closed.

The master control or speed reguatmg switch 33 in idle position engagesthe contact segment 46 so that when the line switch 13 is closed acircuit is closed through the shunt field from the positive conductor10, by conductor 36, segment 37, switch arm 33, segment 46, conductor 58through field F and by conductor 58' to the negative main 11. Thesegment 46 is of such length that the switch arm remains in engagementtheretacts 31 and 32. When the switch arm I ductor 59 is interposed inthe circuit of the relay 30- and somewhat reduces the flow of currenttherethrough but the latter still holds its contacts 31 and 32 closed.When the switch arm engages the segment 42, a circuit can be tracedtherefrom through a conductor 61in which the normally closed push buttoncontacts 54 and 49 are included to the relay contacts 31 and then byconductor 62 and contacts 64 through the energizing coil of the startingswitch 15 to the negative main 11. The conductor 61 is connected to theconductor 59 by a resistance 63 so that, with the switch arm 33 inengagement with the segment 42, a holding circuit is closed fromconductor 61 through resistance 63, conductor 59 and coil of relay 30.The contacts of the latter are thus held closed, the movable contact ofthe starting switch is engaged with its fixed contact 25 and thearmature circuit is closed through the resistance 14, so that the motorwill then start and continue in operation at slow speed. The startingswitch is preferably provided with normally closed contacts 64interposed in its energizing circuit and in shunt to a protectiveresistance 65. When the switch is operated, the contacts 64 are openedand the protective resistance 65 is introduced into its energizingcircuit to reduce the flow of current through its coil. As the controlswitch arm 33 is moved over the contacts 40 and 41, it connects theconductor 59 to the positive supply main and energizes the relay 30, asdescribed, to close contacts 31 in the energizing circuit of thestarting relay, but on account of the resistances 63 and 60, suflicientcurrent will not flow through the contacts 31 to operate the startingswitch until the switch arm engages the segment 42 and thereby closesthe energizing circuit of the starting switch around the resistances 63and 60.

After the motor is thus started to operate at slow speed, it cambefurther accelerated by shifting the switch arm to successively engagethe contacts 43, 44 and 45 to close the circuits of the accelerating orresistance switches 17, 18 and 19. The coils of these switches areinterposed between the positive supply conductor-10 and the negativepole of the motor and are thus energized by the counter electromotiveforce developed by the They are also so arranged that, when in circuit,these coils will operate suc-.

motor.

cessively to reduce the resistance in the armature circuit as the motoraccelerates and reaches difierent predetermined speeds. Thus, while therunning speed is determined by the position of the manually operablecontrolling switch arm 33, the rate of acceleration is automaticallycontrolled in accordance with the load on the motor.

'The coils of the resistance switches are preferably arranged in seriesand each switch, except the last to operate-that is to say, theresistance switches 17 or 18, are provided with normally closed contacts66 and 67 which serve, respectively, to close shunts around the coils ofthe succeeding switches 18 and '19. The resistance switch 19, which isthelast to operate, is also provided with contacts 68 which in normal oridle condition close a shunt around a resistance 69 which is interposedin the energizing circuit of the resistance switches.

When the controlling switch arm is in engagement with the contact 43, acircuit can be traced therefrom by a conductor 70, conductor 71 leadingthrough the contacts 32 of the relay'30 and the upper contacts of thepush button switch 50, thence through the coil of the first resistanceswitch 17 and by conductor 23, contact 25, which is then engaged by themovable contact of the starting switch, and conductor 27 to the negativepole of the armature. Then, when suflicient counter electromotive forceis developed in the armature circuit, the switch 17 is operated to cutout a portion of the armature resistance and open the contact 66 and theshunt around the coil of the resistance switch 18. When the switch arm33 engages the contact 44 and when the first resistance switch 17 hasbeen operated, a circuit may be traced from the controlling switch arm33, contact 44, conductor 72 through the coil of the switch 18 andthence by conductors 73 and 71, through the coil of the first resistanceswitch 17 and back as before to the negative pole of the armature. Whenthe controlling switch arm 33 engages the contact segment 45 and afterthe first and second resistance switches have been operated, a circuitis closed from the switch arm by contact 45, conductor 74, contacts 68,through the coil of the resistance switch 19 by conductor 75, throughthe coil of the resistance switch 18, conductors 73 and 71 to the coilof the first resistance switch 17 and back as before to the negativepole of the armature. When the last resistance switch 19 is operated, itopens the contact 68 and introduces the protective resistance 69 intothe energizing circuit of the coils of the rement 45; When this occurs,the current'is traced from segment 45 by conductor 74,

- contacts 68, 67 and 66 and conductors 73 and 71 through the coil ofswitch 17. When switch 17 operates, it opens contacts 66 and includesthe coil of switch 18 in the circuit and the operation of the latteropens the shunt contacts 67' around the coil of switch 19. While thecircuits of the resistance switches are thus closed by the controlswitches and shunt contacts 66 and 67, they are responsive only todifferent conditions established in the armature circuit and ate themotor. If the reduction of the field current causes an excessive flow ofcurrent in the armature circuit, the field relay 20 operates to closethe contacts and thereby close a shunt around the field resistance. Thefield circuit is then closed from positive conductor 10, by a conductor76, field relay contacts, conductors 77 and 58, through the vfield F andby conductor 58' back to the negative supply main. This rel-ay isarranged to close andopen the shunt around the field resistancerepeatedly until proper conditions are established in the motor circuit.The controlling switch arm 33 canbe quickly shifted to any one of itsrunning positions to determine any oneof a number of different speeds bycooperation with the armature resistance switches 17, 18 and '19 and thefield resistance '47, but the motor circuit is automatically protected,since conditions-established therein control the rate of accelerationefi'ected bythe switches 17 18' and 19 and the operation of the fullfield relay 20. Obviously, the controlling switch arm 33 can be shiftedfrom any of its running positions to reduce the field resistance andsuccessively open the circuits of resistance switches 19, 18 and 17starting switch 15 and relay 30 to decelerate the motor as required orto stop the motor.

In any of the running positions of the master control or speedregulating switch 33, the motor can be stopped by depressing thepush-buton 49 to open the conductor 61 and de-energize the holdingcircuit of the relay 30 and the energizing circuit of the startingswitch 15. The release of the stop pushbutton 49 closes its contacts inthe conductors 61, but resistance 63 prevents energizat-ion of the relay30 so that the relay contacts-31 in the circuit of the starting switchremain open. The motor can then be started by depressing the push-button50 to close a circuit from the supply conductor 36, by a conductor 78,normally engaged contacts 55, conductor 79, through the lower contactsof the push-button switch 50 and thence by the conductors 80 and 59through the coil of relay 30. The latter then operates to engagecontacts 31 and, since the conductor 61 is then connected by the speedcontrolling switch 33 to supply conductor 36, the holding circuit of therelay 30 through the resistance 63 and the energizing circuit of thestarting switch are re-established. The latter then closes the armaturecircuit and starts the motor for continuous operation.

The operation of relay 30 also engages its contacts 32 and the releaseof the push-button 50 connects its'upper contacts so that the circuit ofthe resistance switches is closed at these points and the motor willautomatically accelerate to a speed determined by the position of themaster control or speed regulating switch arm 33. Thus, in any of therunning positions of the switch arm 33, the stop and run buttons-49 and50 can be depressed and released to stop and again start the motor andeffect its acceleration to any one of a number of different speeds, therate of acceleration, as noted before, being controlled automatically inacordance with conditions established 1n the motor circuit and the loadon the motor.

After the motor is stopped it can be started for continuous operation atslow speed in any of the running positions of the main control switch,by depressing the run button 50 and partially rotating it so that, whenreleased, the lug 54 thereon will engage the holding plate 53. Thisoperation will energize relay 30 and starting switch 15 as described butwill not close the circuit of the accelerating switches. In anyposition, and independently of the master control switch, the motor,when stopped, can be started for limited running by depressing the inchpushbutton switch 51. A circuit is then closed through conductors 36, 78, 7 9, the contacts of the inch but-ton, conductors 81 and 62, contacts64 and the coil of the starting switch 15. This circuit is closedindependently of the relay 30, so that the starting switch only remainsenergized as long as the inch button is held depressed. The contacts 55are interposed in the feed conductors 78 and 79 for the run and inchbuttons and the contacts 54 are interposed in the conductor 61 whichsupplies current to the holding circuit of the relay 30 and to theenergizing circuit of the starting switch. By depressing the safebutton, contacts 54 and 55 are opened so that the motor cannot bestarted either by the main control switch or by the auxiliarypush-button switches until the on button is depressed to again closethese contacts.

In any of the running positions of the main control switch, the motorcan be stopped, as stated, by depressing the .pushbutton switch 49.Means are provided for then preventing the starting of the motor by thereturn of the main control switch to normal or idle position. If, as theswitch is returned it could simultaneously engage the segment contact 42and the contact button 40, it would energize both the relay 30 and thestarting switch 15 and thus start the motor,

but since the additional contact 41 and resistance are interposedbetween the contacts 40 and 42, the return movement of the switch cannotenergize the relay 30 until it is entirely'disengaged from the segmentcontact 42. .While the additional contact 41 and resistance 60 thusprevent starting under the circumstances noted, they also serve to holdthe relay 30 energized when the control switch 33 is moved forward fromcontact 40 to contact 42, resistance 63 being in sufiicient tode-energize the relay after it has operated. I

With the controlling switch arm 33 in normal position, it can be shiftedin left hand direction, after releasing the shiftable stop 35, to engagethe contact 48. A circuit is then closed from contact 48 by conductor 82through the coil of the reversing switch and the conductor 83 to thenegative supply controller station A, and the contacts of thecontrolling circuit are of the same polarity, so that the manuallyoperable speed regulating and controlling switches and the wiringtherefor can be of a light construction and co'nvenientl located on thepress or other machine driven by the motor. The operator has fullcontrol of the running speed of the motor and can quickly and readilychange the same or start and stop the motor for limited or continuousrunning at slow speed or for continuous running at any one of a numberof different speeds, but under all conditions the acceleration of themotor is automatically controlled by conditions established in thearmature circuit.

Obviously, the manually operable main and auxiliary control switches maybe located at the same or at a number of different stat-ions, asdesired. Other changes maybe made in the details of construction and thearrangement of the circuits set forth, without departure from theessentials of the invention as defined by the claims.

I claim as my invention 1. In combination in a motor controller,electro-Inag'netio starting means, electromagnetic accelerating meansautomatically responsive to difi'er'ent electric conditions establishedinthe motor circuit, a speed control switch arranged to variably limitthe operation of said accelerating means and thereby determine therunning speed of the motor, and auxiliary control push-button switchesoperable to stop and start the motor.

2. In combination in a motorcontroller, electro-magnetic starting means,electromagnetic accelerating means automatically responsive to differentelectric conditions established in the motor circuit, a speed controlswitch arranged to variably limit the operation of said acceleratingmeans and speed of the thereby determine the running n} push-butt'omotor, and auxiliary contro switches one operable to de-energize saidstarting and accelerating means and the other operable to energize saidstarting means and variably control said accelerating means inaccordance with the setting of said speed control switch and therebystart the motor and effect automatic acceleration thereof in accordancewith the load to any one of a number of different predetermined speeds.

3. In combination in a motor controller, electro-magnetic -startingmeans, electromagnetic accelerating means automatically responsive todiiferent electric conditions established in the motor circuit, a eedcontrol switch arranged to variably imit the operation of saidaccelerating means and thereby determine the running speed of the motor,and auxiliary control push-button switches operable to stop the motorand start the same for limited operation at slow speed or for continuousoperation at a speed determined by the setting of said speed controlswitch.

4. In combination in a motor controller, electro-magnetic startingmeans, electromagnetic accelerating means automatically responsive todifierent electric conditions established in the motor circuit, a speedcontrol switch arranged to variably limit the operation of saidaccelerating means and thereby determine the running speed of the motor,and auxiliary control, push-button switches, one'operable to stop themotor andanother operable to start the motor for continuous operation atslow speed or at a speed determined by the setting of said speed controlswitch.

5. In combination in a motor controller, an electro-ma'gnetic startingswitch, a series of electro-magnetic resistance switches responsivesuccessively, when in circuit, to different conditions established inthe motor circuit, a speed control switch for directing the operation ofone or more of said resistanoe switches to thereby predetermine therunning speed of the motor, and sets of auxiliary control contacts, oneset operable to de-energize said starting and resistance switches andanother operable to energize said starting switch and variably controlsaid resistance switches in accordance with the setting of said speedcontrol switch.

6. In combination in a motor controller, an electro-magnetic startingswitch, a series of electro-magnetic resistance switches responsivesuccessively, when in circuit, to different conditions established inthe motor circuit, a speed control switch for directing the operation ofone or more of said resistance switches to thereby predetermine therunning speed of the motor, and auxiliary control contacts operable totie-energize said starting and resistance switches for stopping and toenergize the same or said starting switch only for running at thepredetermined speed or at slow speed.

7. In combination in a motor controller, an electro-magnetio startingswitch, a series of electro-magnetic resistance switches responsivesuccessively, when in circuit, to difierent conditions established inthe motor circuit, a speed control switch for directing the operation ofone or more of said resistances switches to thereby predetermine therunning speed of the motor, and auxiliary control push-button switchesoperable to deenergize said starting and resistance switches forstopping and to variably control the same 4 for continuous or limitedrunning at slow speed or for continuous running at the predeterminedspeed.

8. In combination in a motor controller, electro-magnetic starting andaccelerating means, a master control switch manually operable to startand stop the motor and effect acceleration thereof to any one of anumber of different speeds and auxiliary control push-button switchesoperable in any of the run positions of said master switch to stop themotor and start the same for running at a speed determined by theposition of said master switch.

9. In combination in a motor controller, electro-magnetic starting andaccelerating means, a master control switch manually operable to startand stop the motor and effect acceleration thereof to any one of anumber of difierent speeds and auxiliary control push-buttonswitches,one operable to stop the motor and another operable to startthe same for continuous running at slow speed or at a speed determinedby the position of said master switch.

10. In combination in a motor controller, electro-magnetic starting andaccelerating means, a master control switch manually operable to startand stop the motor and efl'ect acceleration thereof to any one of anumber of different speeds and auxiliary control push-button switchesoperable to stop the motor and start the same for limited running atslow speed or continuous running at a speed determined by the positionof said master switch.

11. In combination in a motor controller, an electro-magnetic startingswitch, a series of electro-magnetic resistance switches, a mastercontrol switch manually operable to energize the circuit of saidstarting switch and thereafter successively close the circuits of saidresistance switches, said resistance switches being responsiveautomatically and successively as different electrical conditions areestablished in the motor circuit, and auxiliary control push-buttonswitchesoperable, in any of the running positions of the master switch,to de-energize said starting and resistance switches to stop the motorand to variably control the same to start the motor for operation atslow speed or at the speed determined by the position of said masterswitch.

12. In combination in a motor controller, armature and fieldresistances, an electromagnetic starting switch, a series ofelectromagnetic switches for successively cutting out sections of saidarmature resistance, a relay for short circuiting said field resistance,said resistance switches and said field relay being automaticallyresponsive to electrical conditions established in the armature circuit,manually operable speed control contacts cooperating with saidresistance switches and said field resistance to determine the runningspeed of the motor, and

auxiliary manual control contacts operable to stop the motor and againstart the same for operation at a speed determined by the setting ofsaid speed control contacts.

13. In combination in a motor controller, armature and fieldresistances, an electromagnetic starting switch, a series ofelectromagnetic switches for successively cutting out sections of saidarmature resistance, a relay for short circuiting said field resistance,said resistance switches and said field relay being automaticallyresponsive to electrical conditions established in the armature circuit,a manually operable speed control switch having a series of contactsconnected to the circuits of said resistance switches and to thesections of said field resistance and cooperating therewith to determinethe running speed, and an auxiliary control pushbutton switch operableto stop and start the motor for operation at slow speed or at a speeddetermined by the position of said speed control switch.

14:. In combination in a motor controller, an electro-magnetic startingswitch, a series of electro-magneticresistance switches automaticallyand successively responsive, when in circuit, to different conditionsestablished in the motor circuit, and push-button control switches, oneoperable to open the circuits of said starting and resistance switches,another operable to close said circuits and a third operable to closethe circuit of said starting switch alone.

15. In combination in a motor controller, an electro-magnetic startingswitch, aseries of electro-magnetic resistance switches automaticallyand successively responsive, when in circuit, to different conditionsestablished in the motor circuit, a relay having contacts in thecircuits of said starting and resistance switches, and push-buttoncontrol switches operable to open and close the circuit of said relay orto close the circuit of said starting switch independently of saidrelay.

16. In combination in a motor controller, an e'lectro-magnetic startingswitch, a series of electro-magnetic resistance switches automaticallyand successively responsive, when in circuit, to different conditionsestablished in the motor circuit, a relay having contacts in thecircuits of said starting and resistance switches, a master controlswitch manually operable to close and open the circuits of said relayand said starting switch and cooperate with said resistance switches todetermine the running speed of the motor, and auxiliary controlpush-button switches for opening and closing the circuit of said relayand for closing and opening the circuit of said starting switchindependently of said relay.

17. In combination in a motor controller, a

an electro-magnetic starting switch, a series of electro-magneticresistance switches automatically and successively responsive, when incircuit, to different conditions established in the motor circuit, arelay having contacts for opening and closing the circuits of saidstarting and resistance switches and manually operable control contactsfor variably controlling the circuits of said relay and of said startingswitch to stop the motor and start the same for limited or continuousrunning.

18. In combination in a motor controller, an electro-magnetic startingswitch, a series of electro-magnetic resistance switches automaticallyand successively responsive,'when in circuit, to different conditionsestablished in the motor circuit,- a relay having contacts in thecircuits of said starting and resistance switches and separate manuallyoperable speed regulating and controlling switches arranged to variablycontrol the circuits of said relay and of said starting and resistanceswitches to start and stop the motor and effect limited running thereofat one speed or continuous running at any one of a number of differentspeeds.

19. In combination in a motor controller, electro -ma netic s artingmeans, electromagnetic accelerating means, a master control switcharranged to successively cooperate with said starting and acceleratingmeans to start the motor and effect acceleration thereof to any one of anumber of different speeds, an auxiliary push-button switch operable inany of the run positions of said master switch to stop the motor, and

returned to idle position after the stopping of the motor.

21. In combination in a motor controller, an electro-magnetic startingswitch, an electro-magnetic accelerating switch, a relay' havingcontacts in the circuits of said starting and accelerating switches, amaster control switch having a series of contacts adapted tosuccessively close the circuits of said relay, said starting switch andsaid accelerating switch, and auxiliary control contacts for opening andclosing the circuit of said relay to stop and start the motor.

22. In combination in a motor controller,

an electro-magnetic starting switch, an electro-magnetic acceleratingswitch, a relay having contacts in the circuits of said starting andaccelerating switches, a master control switch having a series ofcontacts adapted to successively close the circuits of said relay, saidstarting switch and said accelerating switch, auxiliary controlpush-button switches for opening and closing the circuit of said relayto stop and start the motor, and an additional contact and a resistanceinterposed between the relay and starting switch contacts of said masterswitch for preventing energization of said starting switch as saidmaster switch is returned to idle position after stopping of the motor.

23. In combination in a motor controller, an electro-magnetic startingswitch, an electro-magnetic accelerating switch, a relay having contactsin the circuits of said starting and accelerating switch, a mastercontrol switch having a series of contacts adapted to successively closethe circuits of said relay, said starting switch and said acceleratingswitch, a resistance interposed between the circuits of said relay andsaid starting switch and constituting part of aholding tween the relayand. starting switch contacts, a resistance interposed between saidadditional contact and the circuit of said relay, and an auxiliarycontrol push-button switch for opening the holding circuit of saidrelay.

24. In combination in a motor controller, electro-magnetic starting andaccelerating means, a master control switch normally 0perable to startand stop the motor and effect its acceleration to any one of a number ofdifferent speeds, and auxiliary control pushbutton switches, certain ofwhich are operable for starting and stopping and another adapted to beset in position to prevent starting either by said master switch or bythe starting push-button.

25. In combination in a motor controller, separate electro-magneticstarting and reversing switches having normally engaged and disengagedcontacts and arranged to cooperate to start and reverse the motor,electro-magnetic accelerating means automatically responsive, when incircuit, to conditions established in the motor circuit, and a mastercontrol switch having contacts for separately closing the circuits ofsaid starting and reversing switches and a series of contacts forcontrolling the operation of said accelerating means.

26. In combination in a motor controller, separate electro-magneticstarting and reversing switches having normally engaged and disengagedcontacts and arranged to cooperate to start and reverse the motor,electro-magnetic accelerating means auto matically responsive, when incircuit, to conditions established in the motor circuit, a mastercontrol switch having contacts for separately closing the circuits ofsaid starting and reversing switches and a series of contacts forcontrolling the H operation of said accelerating means, an auxiliarypushbutton switch for opening the circuit of said starting switch andsaid accelerating means to stop the motor, and a brake resistanceinterposed between the normally engaged contacts of said starting andreversing switches. 27. In combination in a motor controller, armatureand field resistances, an electromagnetic starting switch,electro-magnetic accelerating switch mechanism responsive automaticallyto conditions established in the motor circuit for controlling saidarmature resistance, a relay responsive to abnormal conditions in themotor circuit for short circuiting said field resistance, said startingswitch being arranged to close the circuit of said relay independentlyof said accelerating switch mechanism, and manually operable contactsfor controlling said starting switch, said accelerating switch mechanismand said field resistance to effect the operation of the motor at anyone of a number of difierent speeds.

28. In combination in a motor controller,

a series of successively operating electromagnetic resistance switcheshaving their coils connected in series, and manually operablespeed-regulating contacts for successively closing the circuits of saidswitches,

each resistance switch, except the last to operate, being arranged inoperating to open a short circuit around the coil of the succeedingswitch.

29. In combination in a motor controller, a series of successivelyoperating electromagnetic resistance switches having their coilsconnected in series, a manually operable, speed regulating switch havinga series of contacts for successively closing the circuits of saidswitches, each resistance switch, except the last to operate, beingarranged in operating to open a short circuit around the coil of thesucceeding switch, and means controlled by the complete operation ofsaid switches for reducing the flow of current through the coilsthereof.

30. In a motor controller, the combination of controlled and controllingcircuits, an electro-magnetic starting switch and one or moreelectro-magnetic accelerating switches having contacts in the controlledcircuit and energizing coils in the controlling circuit, saidaccelerating switch or switches being responsive to predeterminedconditions established in the motor circuit, a manually operable switchin the controlling circuit for directing the Operation of saidaccelerating switch or switches and thereby predetermine the runningspeed of the motor, and auxiliary switches in the controlling circuitmanually operable tostart the motor for operation at the predeterminedspeed or at slow speed, and to stop the motor.

31. In a motor controller, the combination with controlled andcontrolling circuits, of a main station comprising an electro-magneticstarting switch and one ormore electromagnetic resistance switches, saidstarting and resistance switches having contacts in the controlledcircuit and energizing coils in .the controlling circuit, and acontrolling station comprising switch contacts in said controllingcircuit for governing the operation of said resistance switch orswitches,

and push button switches in said controlling circuit operable to startthe motor for limited operation at one speed or for continuous operationat different speeds, and to stop the motor.

32. In a motor controller, an electromagnetic starting switch, one onmore electro-magnetic resistance switches responsive to predeterminedconditions established in the motor circuit, energizing and holdingcircuits for said electro-magnetic starting and resistance switches, andsets of manually operable switch contacts for variably controlling saidenergizing and holding circuits to start and stop the motor and efl'ectthe limited operation thereof at one speed or continuous operation atdifferent speeds.

33. In a motor controller, an electromagnetic starting switch, one ormore elect-ro-magnetic resistance switches responsive to predeterminedconditions established- 1n the motor circuit, relay means havingseparate sets of contacts interposed respectively in the energizingcircuits of said starting and said resistance switches, a switch avingcontacts in the energizing circuit of said resistance switch or switchesand manually operable to predetermine the motor speed, and push buttonswitches for variably controlling the circuits of 'saidstartin switchand said relay and operable to start the motor for limited operation orfor continuous operation at different speeds, and to sto the motor.

34. a motor controller, the combination with controlled and controllingcircuits, of an electroamagnfetic starting switch, an electro-magneticreversing switch and an electro-maginetic accelerating switch orswitches, said electro-magnetic switches having contacts in thecontrolled circuit and energizing coils in the controlling circuit, andseparatemanually operable switches having contacts in the controllingcircuit arranged to variably control said electromagnetic switches tostart the motor for forward operation at difl'erent speeds, stop themotor and reverse the same.

35. In a motor controller, the combination with a motor circuit and acontrolling circuit, of a series of electro-magnetic resistance switcheshaving coils connected in series in the controlling circuit and arrangedto respond automatically and successively to conditions established inthe motor circuit, and a manually operable, speed regulating switch inthe controlling circuit for determining the operation of one or more ofsaid resistance switches, each resistance switch, except the last tooperate, being arranged to open a short circuit around the coil of thesucceeding switch.

36. In combination in a motor controller, separate electro-magneticstarting and reversing switches, each having a movable contact andnormally engaged and disengaged relatively fixed contacts and said gswitches being arranged, when either one is operated, to supply currentto the motor through the normally engaged contact of one switch and thenormally disengaged contact of the other switch, and manually operablecontacts for separately controlling the energizing circuits of saidelectromagnetic starting and reversing switches.

37. In combination in a motor controller, separate electro-magneticstarting and reversing switches, each having a movable contact andnormally engaged and disengaged relatively fixed contacts, currentsupply conductors, one connected to the normally engaged contacts ofsaid starting and reverslng switches and; the other to the normallydisengaged contacts of said switches, a motor having its terminalsconnected to the movable contacts of said switches, a brake resistanceinterposed between the normally engaged contacts of said switches, andcontrolled contacts for separately energizing the circuits of saidswitches.

ALLAN J. CLINE.

